import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.FutureTask;

public class Demo12 {

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        //Thread thread = new Thread(Callable);

        //此处 Callable 只是定义了一个“带有返回值”的任务
        //并没有真的在执行，执行还是需要搭配 Thread 对象。
        Callable<Integer> callable = new Callable<Integer>() {
            @Override
            public Integer call() throws Exception {
                int result = 0;
                for (int i = 1; i <= 1000; i++) {
                    result += i;
                }
                return result;
            }
        };
        FutureTask<Integer> futureTask = new FutureTask<>(callable);

        Thread t = new Thread(futureTask);
        t.start();

        int result = futureTask.get();
        System.out.println(result);
    }
}
